Compute Module • CM4 /CM5 PCIe_CLK_nREQ

Hi~
I'm using a PCIe 2.0 M.2 KEY SSD.
1. CM4 Datasheet page 7 notes as below.
[Additionally the PCIe_CLK_nREQ must be connected to ensure the CM4 produces a clock signal, and the PCIe_nRST should also be connected to ensure the device is correctly reset when required.]
2. The link below is CM4 PCIe to M.2 Adapter Card. PCIe_CLK_nREQ is n.c, but it works well when installed on ssd.
https://ko.aliexpress.com/item/1005002258572490.html
https://www.amazon.com/DBEIXIWEI-Adapte ... B0DC7GSB8S
3. In the circuit below, PCIe_CLK_nREQ is n.c.
https://files.waveshare.com/upload/a/aa ... SchDoc.pdf

Do I need to connect CM4 pin 102 (PCIe_CLK_nREQ) to SSD nCLKREQ?
Is there a difference in behavior when PCIe_CLK_nREQ is connected and when it is n.c.?
Thanks.

Statistics: Posted by kwon yong gil — Mon May 12, 2025 6:50 am

---